In 2007, Petacchi was banned from cycling and had his results achieved disqualified for doping. The court later said that he had not cheated on purpose but had not taken enough care when consuming his legal asthma drug.[5] He announced his retirement as a lead sprinter on 23 April 2013, and terminated his contract at Lampre–Merida,[4][6] but is now a lead-out man.[7] He rejoined the professional peloton in August 2013, joining the Omega Pharma–Quick-Step squad.[8]

In 2010, he won the first and fourth stages of the Tour de France. Before going on to complete the grand slam as he won the green sprinters jersey to complete the feat at all the grand tours. In so doing he was the 1st person to complete the feat since 1999 and the first Italian to win the points classification in the Tour de France since 1968.[10]

On 6 May 2008, the Court of Arbitration for Sport banned Petacchi until the end of August, applied retroactively from November. It said all competitive results obtained during the 2007 Giro d'Italia shall be disqualified with all of the resulting consequences including forfeiture of any medals, points and prizes. Results after 31 October 2007 and during his ban were disqualified including five Giro d'Italia stage wins. The court said Petacchi had not intended to cheat and that it was likely that he had inadvertently consumed too much medication, but he had not exercised "utmost caution."[13] The case was considered controversial,[14] as it kept Petacchi from starting the Tour de France as he had planned[15] and for the court ruling that he should be suspended despite acknowledging that he had not cheated. Petacchi maintained that he had done no wrong.[16]

He was selected to ride the Giro d'Italia and won the second and third stages, wearing the pink jersey on stage 3 and the cyclamen jersey on stages 2 through 5.[18]

Petacchi signed with Lampre–Farnese Vini for the 2010 season.[19] He announced his retirement after the 2013 Paris–Roubaix, citing a lack of motivation to continue as a lead sprinter. However he subsequently expressed a desire to take up an offer from the Omega Pharma-Quick Step team to ride as a lead-out man for Mark Cavendish, which he said was made to him days after his retirement. The contract offer was blocked by the UCI as it forbids riders from transferring from one team to another mid-season.[20] In July 2013 Patrick Lefevere announced that Petacchi would be joining Omega Pharma-Quick Step from the start of August on a 14-month contract.[8] On 12 April 2014 he got his first victory for his new team at Grand Prix Pino Cerami and also his first victory since 2012. In January 2015 it emerged that Petacchi would ride for Southeast Pro Cycling in 2015.[1] However, after racing in that year's Giro at the age of 41 and being forced to withdraw from the race one day before its conclusion due to a virus, Petacchi announced his second retirement from the sport in June 2015.[21]